Regeneration of Bone- and Tendon/Ligament-Like Tissues Induced by Gene Transfer of Bone Morphogenetic Protein-12 in a Rat Bone Defect

Members of the bone morphogenetic protein (BMP) family have diverse physiological roles. For instance, BMP-2 stimulates osteogenesis, while BMP-12 induces the formation of tendon/ligament-like tissues. Here, we designed a study to determine whether BMP-12 has bone and/or cartilage regeneration abilities similar to those of BMP-2. We implanted plasmid vectors encoding either BMP-2 or BMP-12 in rats with femur defects, and monitored the bone healing process for 8-weeks. The BMP-12 transgene induced prominent fibrogenesis by 2 weeks, with bone substitution occurring by 8 weeks. BMP-2, however, was associated predominantly with osteogenesis throughout the 8 week period. Thus, we conclude that BMP-12 does not function similarly to BMP-2 during bone healing. Further work is needed to better understand the mechanisms by which it stimulates bony growths to replace the connective tissues formed during the first stages of bone healing

NF-κB inhibitor dehydroxymethylepoxyquinomicin suppresses osteoclastogenesis and expression of NFATc1 in mouse arthritis without affecting expression of RANKL, osteoprotegerin or macrophage colony-stimulating factor

Inhibition of NF-κB is known to be effective in reducing both inflammation and bone destruction in animal models of arthritis. Our previous study demonstrated that a small cell-permeable NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), suppresses expression of proinflammatory cytokines and ameliorates mouse arthritis. It remained unclear, however, whether DHMEQ directly affects osteoclast precursor cells to suppress their differentiation to mature osteoclasts in vivo. The effect of DHMEQ on human osteoclastogenesis also remained elusive. In the present study, we therefore examined the effect of DHMEQ on osteoclastogenesis using a mouse collagen-induced arthritis model, and using culture systems of fibroblast-like synovial cells obtained from patients with rheumatoid arthritis, and of osteoclast precursor cells from peripheral blood of healthy volunteers. DHMEQ significantly suppressed formation of osteoclasts in arthritic joints, and also suppressed expression of NFATc1 along the inner surfaces of bone lacunae and the eroded bone surface, while serum levels of soluble receptor activator of NF-κB ligand (RANKL), osteoprotegerin and macrophage colony-stimulating factor were not affected by the treatment. DHMEQ also did not suppress spontaneous expression of RANKL nor of macrophage colony-stimulating factor in culture of fibroblast-like synovial cells obtained from patients with rheumatoid arthritis. These results suggest that DHMEQ suppresses osteoclastogenesis in vivo, through downregulation of NFATc1 expression, without significantly affecting expression of upstream molecules of the RANKL/receptor activator of NF-κB/osteoprotegerin cascade, at least in our experimental condition. Furthermore, in the presence of RANKL and macrophage colony-stimulating factor, differentiation and activation of human osteoclasts were also suppressed by DHMEQ, suggesting the possibility of future application of NF-κB inhibitors to rheumatoid arthritis therapy

The inhibitory effects of a RANKL-binding peptide on articular and periarticular bone loss in a murine model of collagen-induced arthritis: a bone histomorphometric study

Showing the effects of OP3-4 on the proliferation and differentiation of cartilage cell line ATDC5. A Results of proliferation assay on day 1 with the noninduction medium. B Alcian blue-positive area ratio in the cartilage induction medium on day 10. **p <0.01 vs. vehicle control, #p <0.05 vs. 100 ÎźM OP3-4. (JPEG 384 kb

Details on the effect of very short dual antiplatelet therapy after drug-eluting stent implantation in patients with high bleeding risk: insight from the STOPDAPT-2 trial

Previously we briefly reported the effect of 1-month dual antiplatelet therapy (DAPT) for patients with high bleeding risk (HBR) receiving percutaneous coronary intervention (PCI) in the STOPDAPT-2 trial, but full analysis data have not been available. We conducted post hoc subgroup analysis regarding the effect of very short DAPT for HBR patients in STOPDAPT-2 trial. The primary endpoint was a 1-year composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) and bleeding (TIMI major/minor bleeding) outcomes. Major secondary endpoints were 1-year cardiovascular composite endpoint and bleeding endpoint. HBR was defined by the academic research consortium (ARC) HBR criteria. Among the 3009 study patients, 1054 (35.0%) were classified as HBR and 1955 (65.0%) were as non-HBR. There were no significant interactions between HBR/non-HBR subgroups and the assigned DAPT group on the primary endpoint (HBR; 3.48% vs. 5.98%, HR 0.57, 95% CI 0.32-1.03, and non-HBR; 1.81% vs. 2.36%, HR 0.78, 95% CI 0.42-1.45; P for interaction = 0.48), the major secondary cardiovascular endpoint (HBR; 3.07% vs. 4.03%, HR 0.77, 95% CI 0.40-1.48, and non-HBR; 1.41% vs. 1.61%, HR 0.89, 95% CI 0.43-1.84; P for interaction = 0.77), and the major secondary bleeding endpoint (HBR; 0.41% vs. 2.71%, HR 0.15, 95% CI 0.03-0.65, and non-HBR; 0.40% vs. 0.85%, HR 0.48, 95% CI 0.14-1.58; P for interaction = 0.22). In conclusion, the effects of 1-month DAPT for the primary and major secondary endpoints were consistent in HBR and non-HBR patients without any significant interactions. The benefit of 1-month DAPT in reducing major bleeding was numerically greater in HBR patients.Clinical trial registration Short and optimal duration of dual antiplatelet therapy after everolimus-eluting cobalt-chromium stent-2 [STOPDAPT-2]; NCT02619760

A novel underuse model shows that inactivity but not ovariectomy determines the deteriorated material properties and geometry of cortical bone in the tibia of adult rats

Our goal in this study was to determine to what extent the physiologic consequences of ovariectomy (OVX) in bones are exacerbated by a lack of daily activity such as walking. We forced 14-week-old female rats to be inactive for 15 weeks with a unique experimental system that prevents standing and walking while allowing other movements. Tibiae, femora, and 4th lumbar vertebrae were analyzed by peripheral quantitative computed tomography (pQCT), microfocused X-ray computed tomography (micro-CT), histology, histomorphometry, Raman spectroscopy, and the three-point bending test. Contrary to our expectation, the exacerbation was very much limited to the cancellous bone parameters. Parameters of femur and tibia cortical bone were affected by the forced inactivity but not by OVX: (1) cross-sectional moment of inertia was significantly smaller in Sham-Inactive rat bones than that of their walking counterparts; (2) the number of sclerostin-positive osteocytes per unit cross-sectional area was larger in Sham-Inactive rat bones than in Sham-Walking rat bones; and (3) material properties such as ultimate stress of inactive rat tibia was lower than that of their walking counterparts. Of note, the additive effect of inactivity and OVX was seen only in a few parameters, such as the cancellous bone mineral density of the lumbar vertebrae and the structural parameters of cancellous bone in the lumbar vertebrae/tibiae. It is concluded that the lack of daily activity is detrimental to the strength and quality of cortical bone in the femur and tibia of rats, while lack of estrogen is not. Our inactive rat model, with the older rats, will aid the study of postmenopausal osteoporosis, the etiology of which may be both hormonal and mechanical

EFFECTS OF COLCHICINE ON OSTEOBLAST IN RAT: AN ULTRASTRUCTURAL STUDY

The present study was an attempt to investigate the effects of colchicine on the ultrastructure of rat osteoblasts with special reference to the microtubular function in vivo. Rats were killed at intervals of 2, 4, 8, 12 and 24 hours after the colchicine injection (0.1mg per 100g of body weight, subcutaneously). At 2 and 4 hours after the injection, the secretory granules and small vesicles accumulated in the Golgi area of the osteoblasts. The dilated spherical cisterna of the rough endoplasmic reticulum and the large vacuoles appeared, being located in the periphery of the cell. Microtubules were rarely found in the cytoplasm. Small masses of microfilaments of 80 to 110 A in diameter were found also in the cytoplasm. According to the special staining for collagen, it was indicated that the contents of the secretory granules might be collagen-like materials. At 8 hours after the injection, the shape of the osteoblasts transformed to a round profile and the autophagic vacuoles increased in the cytoplasm. At 12 and 24 hours after the injection, the osteoblasts seemed to be destroyed by the breakdown of the plasma membrane and by the increase of the autophagic vacuoles. It is suggested that colchicine affects the secretory process of the bone matrix and the cytoskeletal system of the osteoblasts by interfering with the structure and the function of the microtubules and colchicine also interferes with the function of the plasma membrane followed by the destruction of the osteoblasts

The Effect of Bisphosphonate on The Osteoclast-Like Cell Formation in A Mouse Bone Marrow Culture

Bisphosphonates are reported to have an inhibitory effect on bone resorption in vivo and in vitro. The present study examined the effect of bisphosphonate on the formation of osteoclast-like cells in vitro. When mouse bone marrow cells were cultured for 8 days with 108M 1α, 25-dihydroxyvitamin D3 (1α, 25(OH)2D3) numerous clusters of mononuclear and multinucleated cells formed, which stained positive for tartrate-resistant acid phosphatase (TRAP-positive). 1α, 25(OH)2D3 is known to stimulate osteoclast-like cell formation in a mouse bone marrow culture. Adding 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) inhibited the increased formation of osteoclast-like cells stimulated by this stimulant. A time-course experimental model showed that the number of osteoclast-like cells decreased slightly when drugs were given early in the culture period and decreased markedly when the drugs were given later or continuously in the culture period. These findings suggested that bisphosphonate had an effect on mature stage and significantly inhibit bone destruction by inhibit osteoclast-like cells formation. The amount of PGE2 production stimulated by 1 α, 25(OH)2D3 was dose depedently higher with HEBP and 3-amino-1-hydroxypropylidene-1, 1-bisphosphonate (APD). Showing that PGE2 production is high at the end of culture when the cells are going to undergo apoptosis. This showed in part, the known bone-resorbing activity of these agents.</p

The Effect of Bisphosphonate on The Osteoclast-Like Cell Formation in A Mouse Bone Marrow Culture

Bisphosphonates are reported to have an inhibitory effect on bone resorption in vivo and in vitro. The present study examined the effect of bisphosphonate on the formation of osteoclast-like cells in vitro. When mouse bone marrow cells were cultured for 8 days with 108M 1α, 25-dihydroxyvitamin D3 (1α, 25(OH)2D3) numerous clusters of mononuclear and multinucleated cells formed, which stained positive for tartrate-resistant acid phosphatase (TRAP-positive). 1α, 25(OH)2D3 is known to stimulate osteoclast-like cell formation in a mouse bone marrow culture. Adding 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) inhibited the increased formation of osteoclast-like cells stimulated by this stimulant. A time-course experimental model showed that the number of osteoclast-like cells decreased slightly when drugs were given early in the culture period and decreased markedly when the drugs were given later or continuously in the culture period. These findings suggested that bisphosphonate had an effect on mature stage and significantly inhibit bone destruction by inhibit osteoclast-like cells formation. The amount of PGE2 production stimulated by 1 α, 25(OH)2D3 was dose depedently higher with HEBP and 3-amino-1-hydroxypropylidene-1, 1-bisphosphonate (APD). Showing that PGE2 production is high at the end of culture when the cells are going to undergo apoptosis. This showed in part, the known bone-resorbing activity of these agents

Thermochemical Performance of a Lightweight Charring Carbon Fiber Reinforced Plastic

A new class of lightweight carbon fiber reinforced plastic (CFRP)–-the lightweight ablator series for transfer vehicle systems (LATS)–-has recently been developed. The LATS is fabricated by heating and pressurizing a material in which resin is impregnated in the laminated carbon fiber felt. A characteristic required to ensure the excellence of a conventional lightweight CFRP ablator of the LATS is the simplicity of the resin impregnation process. Since dried bulk density can be easily controlled, this manufacturing method is beneficial for use in the aerospace industry. Here, the ablation characteristics of this material under high-enthalpy airflow are described by a recently developed computer code to simulate the one-dimensional transient thermal behavior. The validity of the mathematical model and the applicability of the ablation code are then discussed by comparing the simulated and experimental results of arc-heated tests with the LATS. A new index adopted in this study predicted the mass loss rate; the measured and estimated values of the total mass loss rate in various test conditions are in good agreement. Thus, a heated LATS material shows excellent performance characteristics for use in re-entry vehicles, and its surface and in-depth temperatures can be estimated using the developed analysis code